The SP-55 TS ROS 2-stroke single cylinder with 55 ccm is the largest single cylinder engine in the Sky Power lineup. It is equipped in the standard configuration with a twin ignition unit. The carburetor is top mounted.
It is designed with twin spark plugs and a top-mounted carburetor. The Rear Output Shaft (ROS) makes this engine one of the most compact one-cylinder engines on the market.
Because of the rear output shaft, a generator can be mounted on the back of the engine.
The engine is used by customers for fixed wing, heli and VTOL aircraft on the upper end of the ‘below 55 lb’ or ‘up to 25 kg’ class UAS as well as hybrid configurations to produce electricity.
The cylinder is casted aluminum and has been manufactured in its current form for over ten years. The Crankcase is CNC machined in order to be able to adjust customer specific parts to it.
| Type | 1-Cylinder Gas Engine |
| Capacity | 55 ccm / 3.35 cu in |
| Power | 3.9 HP / 2.9 KW @ 6500 RPM |
| Speed Range | 2200 – 10000 RPM |
| Weight | incl. ignition 5.68 lbs (2.58 kg) |
| Crankshaft | 4 ball bearings |
| Oil/Gasoline ratio | 1:50 / 2% mix |
| Operating Voltage | 6 – 8.4 V DC |
| Bore diameter | 1.77 inch (45.00 mm) |
| Stroke | 1.38 inch (35.00 mm) |
| Torque | 4.7 Nm @ 5500 RPM |
